In 1984, he began his career as a journalist.[3] His book Political Punch is a critique of politics and society in Israel. Between 2003 and 2014, Yemini has been the opinion page editor of Maariv.

In 2014 Yemini began writing for the daily Yedioth Ahronoth. In 2014 he published a book The Industry of Lies dealing with anti-Israeli incitement by radical left, human right groups, pro-Palestinians organizations and radical Islam.

Most of his newspaper articles are intended to refute what he regards as anti-Israel claims.[1] He has published articles about the Israeli-Arab conflict in which he examines the issues of genocide, refugees, Palestinian and Arab capital, the status of Israeli Arabs,[4]multiculturalism and the status of women. He argues that "anti-Zionism is politically correct anti-Semitism": the same way Jews were demonized, Israel is being demonized; the same way the right of Jews to exist was denied, the right for self-determination is denied to Israel; and the same way Jews were presented as a menace to the world, Israel is presented as a menace to the world.[5]

Yemini is Zionist and describes himself as a left winger.[6] While considered by some to be conservative,[7] Yemini defends the rights of critics of academic leftists[8] and claims he has been mislabeled as a right-winger and has a "long track record in the Israeli peace camp"; he also claims to have met with Yasser Arafat in Tunis, as well as having several friends who are PLO officials. He is a long-time believer in a two-state solution, and believes Israel should have the same right of self-determination as the Palestinians.[1] In 2012, while being fully supportive of Israel's motive behind Operation Pillar of Defense,[9] Yemini expressed his support in "[making] a move which no one expects – follow a unilateral cease-fire by inviting Hamas to peace talks."[10]